1. Field of the Invention
The present invention relates to a shelf and, more particularly, to a combination shelf for placing articles.
2. Description of the Related Art
A conventional combination shelf in accordance with the prior art shown in FIGS. 6 and 7 comprises a plurality of upright posts 60, a plurality of mounting sleeves 70 each mounted on a respective one of the upright posts 60, and a frame 80 mounted between the upright posts 60 and provided with a plurality of fixing sleeves 82 each detachably mounted onto a respective one of the mounting sleeves 70.
Each of the upright posts 60 has an outer wall provided with a plurality of retaining grooves 61. Each of the mounting sleeves 70 includes two clamping plates 75 detachably combined with each other and each detachably mounted on the respective upright post 60. One of the two clamping plates 75 of each of the mounting sleeves 70 is provided with two opposite slots 74, and the other one of the two clamping plates 75 of each of the mounting sleeves 70 is provided with two opposite plugs 76 inserted into the two opposite slots 74 to combine the two clamping plates 75 of each of the mounting sleeves 70 together. Each of the two clamping plates 75 of each of the mounting sleeves 70 has an inner face provided with a retaining rib 71 locked in any one of the retaining grooves 61 of the respective upright post 60. Each of the two clamping plates 75 of each of the mounting sleeves 70 has a middle portion provided with an elongate slit 72 to make each of the two clamping plates 75 flexible. Each of the two clamping plates 75 of each of the mounting sleeves 70 has a lower end provided with an enlarged stop flange 73. Each of the two clamping plates 75 of each of the mounting sleeves 70 has a tapered outer face. Each of the fixing sleeves 82 of the frame 80 has an inner portion provided with a tapered locking hole 81 detachably locked onto the two clamping plates 75 of the respective mounting sleeve 70 and pressing the tapered outer face of each of the two clamping plates 75. Each of the fixing sleeves 82 of the frame 80 has a lower end abutting and stopped by the stop flange 73 of each of the two clamping plates 75 of the respective mounting sleeve 70.
However, when a user wishes to increase the number of the frame 80 or to adjust the position of the frame 80, the user has to remove the fixing sleeves 82 of the frame 80 from the mounting sleeves 70 and to remove the mounting sleeves 70 from the upright posts 60, and also has to reassemble the mounting sleeves 70 on the upright posts 60 and to reassemble the fixing sleeves 82 of the frame 80 on the mounting sleeves 70, thereby causing inconvenience to the user. In addition, when the locking hole 81 of each of the fixing sleeves 82 has a smaller size, the lower end of each of the fixing sleeves 82 cannot abut the stop flange 73 of each of the two clamping plates 75 of the respective mounting sleeve 70, and when the locking hole 81 of each of the fixing sleeves 82 has a greater size, a clearance is defined between the locking hole 81 of each of the fixing sleeves 82 and each of the two clamping plates 75 of the respective mounting sleeve 70.